A novel diamond-like carbon coating has been developed that has an extremely low work function. Using a proprietary deposition method, this material can be coated on a variety of metal and ceramic parts. Phase I of this project will test the applicability of this material for use as a cold field emission source of electrons to replace hot filaments in electron guns. The concept will first be tested by obtaining emission from a sharp tungsten tip coating with this carbon material, then replacing the hot filament cathode in an electron gun, and finally obtaining preliminary operating parameters (e.g. maximum emission current, emission voltage etc.) for the gun. This information will then be used to design a direct replacement tip for hot filament electron guns. Since this material has a very low work function, the Wehnelt power supply in most electron guns should serve as the extractor supply.
